Glue Line Rip Blades

[Joe Wood]

Are they supposed to leave a slightly scored surface, for the glue to grip better, or are the edges supposed to be real smooth?

[Lisa Starr]

My Freud leaves an absolutely smooth finish.

[Paul F Franklin]

I use a Freud GLR blade and the results are quite smooth, with an occasional slight score mark if I stop feeding to move my hands or whatever. If you're getting a lot of scoring I'd check that your fence is parallel to the blade or just slightly toed out at the far end. A feather board or something like the Jessum table saw guides to keep board tight against the fence helps too.

[glenn bradley]

The blade will leave a smooth surface on a well aligned saw. If your blade and fence are not parallel the blade will leave marks on one side or the other depending on the path deviation.

Poor alignment.

444251

Good alignment.

444252

[Randy Heinemann]

I agree with the rest. I've owned 2 Freud glue line rip blades (one a thin kerf blade). They do leave an almost perfectly smooth finish; at least one that is essentially ready for glue up. I joint my rips anyway to get any slight imperfections out but have, on rare occasions, just glued without jointing.

Stopping the rip in the middle or allowing the board to move even a hair away from the fence during the rip can leave a saw mark. I would imagine that wobble in your blade/arbor would also cause saw marks. Then, as said before, alignment of the fence is important. Other than this, I can't think of anything that would cause saw marks.

[Joe Wood]

OK! I'll go check the alignment right now!

how much toe out do you like to have on the fence?

[glenn bradley]

OK! I'll go check the alignment right now!

how much toe out do you like to have on the fence?


This can start a whole other conversation ;-) I set mine as close as I can get to parallel. Usually within .001 - .002". If you need a toe-out fence I would recommend a sacrificial short fence (https://youtu.be/d7QXIN2X8-w?t=175) instead. I do this when required as it allllows the 'keeper' to fall away if stress release is opening the kerf. This is similar to sliders or western saws equipped with a sliding fence face for this purpose. Here's something on positioning (https://www.youtube.com/watch?v=ep3Gpu4gEZA) the short fence.

[Phillip Mitchell]

Ideally none, but some people think that a few thousandths is beneficial.

Do you have a riving knife or splitter on your saw?

[Joe Wood]

That was it Phillip! The left side of the kerf was just hitting the splitter, bumping it off the fence a tiny bit, so I put a thin washer on one side of it,

and now I'm getting nicer cuts!

[Tony Joyce]

Are they supposed to leave a slightly scored surface, for the glue to grip better, or are the edges supposed to be real smooth?

A true straight line rip saw (used for glue line rips) ,with proper blade, will leave a slight crosshatch pattern on the wood for good adhesion.

This is what was conveyed to me as proper by people who sold the machinery and people using them in factories.
This has served me well for years and many thousands of feet of glue ups.

[Frank Pratt]

For PVA wood glue, there is no need at all for surface roughness for the glue to bond.

[Mel Fulks]

For PVA wood glue, there is no need at all for surface roughness for the glue to bond.

Agree....and throw in the other glues. Some ADHESIVES might benefit from rough surface.

[Joe Wood]

This is mostly 2x and up, clear wr cedar I'm usually ripping with a 12" blade.

I suspected it was meant to leave a slight scoring, I'm not too bothered with it but,

what type blade would give me an almost smooth rip??

[Derek Cohen]

Joe, when I use my Hammer K3 is tablesaw mode, it is done with the JessEm guides. This forces the workpiece to hug the rip fence. The lack of wandering aids hugely to a smooth cut - with just about any blade.

When I use the K3 in slider mode, it effectively does the same thing (as long as the workpiece does not move - hence the new fixture I posted here very recently) - the cut and the blade do not wander, even minutely.

Regards from Perth

Derek

[Jeff Ranck]

Joe, when I use my Hammer K3 is tablesaw mode, it is done with the JessEm guides. This forces the workpiece to hug the rip fence. The lack of wandering aids hugely to a smooth cut - with just about any blade.
...
Regards from Perth

Derek

I've been looking at those, but I can't figure out how to have both the JessEm guides and my overhead dust collection.

Jeff.

[Rod Sheridan]

OK! I'll go check the alignment right now!

how much toe out do you like to have on the fence?

I have about 0.003” toe out on the fence.

I get glue ready rips, I use a short fence that ends just beyond the start of the blade....Regards, Rod.

[Derek Cohen]

Jeff, it is straightforward. The JessEm guides are on a track, which enables them to be adjusted for spacing/position. Just position them outside the dust guard, as I do.

With the down hose removed ...

https://i.postimg.cc/VLGK100n/Y1a.jpg

Regards from Perth

Derek

[Jeff Ranck]

as always my friend, thank you so much!

[kent wardecke]

Agree....and throw in the other glues. Some ADHESIVES might benefit from rough surface.

Thanks, I was wondering about that

[Erik Loza]

Derek, I really like your router lift setup.

Erik

[Joe Wood]

OK folks, I'd like another 12" rip blade that leaves a smooth cut without the cross hatching. I mostly rip softwoods, 2x and 4x, hardly ever hardwoods or sheet goods, so no combo blades or thin kerf please,

so what would you recommend for me?

[Erik Loza]

Joe, I think any of the good brands (Forrest, Tenryu, etc.) could give you a decent cut but it's a rip blade, so not sure you will get "finish-quality" results like a glue-line blade. Are you just not wanting to sand, or?

Erik

[Bruce King]

If you don’t have a jointer just run the board through the TS a 2nd time to take off just .100 or less to clean up the edge. Don’t stop or slow down. Most any decent blade will be fine using this method. Are you sure the board is flat on the saw and fence with zero wobble?

[Joe Wood]

Yeah just to cut down on the hand sanding because I don't have a jointer.